Masakazu Yamashita

New chiral phosphine–amide ligands in palladium-catalysed asymmetric allylic alkylations

Abstract Palladium-catalysed asymmetric allylic alkylation of 1,3-diphenyl-2-propenyl acetate 8a with a dimethyl malonate–BSA–LiOAc system has been successfully carried out in the presence of new chiral phosphine–amide, such as 5, in good yields and high enantiomeric excesses of up to 85%.

Gas chromatographic determination and gas chromatographic-mass spectrometric determination of dialkyl phosphates via extractive pentafluorobenzylation using a polymeric phase-transfer catalyst

Abstract A GC and GC-MS procedure was established for dialkyl phosphates (DAP), including dialkyl thiophosphates and dialkyl dithiophosphates (alkyl = Me, Et) via extractive pentafluorobenzylation using a polymeric phase-transfer catalyst (tri-phase catalyst). The abilities of five tri-phase catalysts were compared and among them tri- n -butylmethylphosphonium bromide, polymer bound [0.75 mequiv. Br − /g, 200–400 mesh (TB-0.75)], was found to be the most effective. The dialkyl thiosphosates and dialkyl dithiophosphates in an aqueous sample were readily extracted in the form of their pentafluorobenzyl (PFB) derivatives when the reaction mixture consisting of buffered aqueous sample, toluene, pentafluorobenzyl bromide and TB-0.75 was stirred at 45°C. The extractive pentafluorobenzylation of dimethyl phosphate and diethyl phosphate was effetted with an additional reaction at 90°C. It was also found that DAP, even in a relatively large volume of aqueous sample, could be captured efficiently by this catalyst.

Palladium-catalyzed asymmetric allylic substitution using planar chiral hydrazone ligands

Abstract Palladium-catalyzed asymmetric allylic alkylation of 1,3-diphenyl-2-propenyl acetate ( 3 ) with a dimethyl malonate–BSA–LiOAc system has been successfully carried out in the presence of planar chiral phosphine-hydrazone ligands such as 2a in good yields with good enantioselectivities (up to 96% ee).

A Novel Isoindoline, Porritoxin Sulfonic Acid, from Alternaria porri and the Structure-phytotoxicity Correlation of Its Related Compounds

Novel zinniol-related compound 3, named porritoxin sulfonic acid, with an isoindoline skeleton was isolated from the culture liquid of Alternaria porri. The structure was determined to be 2-(2″-sulfoethyl)-4-methoxy-5-methyl-6-(3′-methyl-2′-butenyloxy)-2,3-dihydro-1H-isoindol-1-one. The phytotoxic activities of three isoindolines (1-3) were evaluated in a seedling-growth assay against stone leek and lettuce.

One-and–a-half years since the Fukushima Daiichi nuclear power plant accident, Japan has learned nothing: resumption of nuclear operations

Japans prime minister decided on the resumption of nuclear power plant operations. Following an accident at Tokyo Electric Power Companys Fukushima Daiichi nuclear power plant in March 2011, it has not been clarified where melted-down fuel rods leaked to and what their current status is. Nevertheless, Japan is going to resume nuclear plant operations. This paper summarizes the progress in handling the accident during the past one-and–a-half years, analyzes the status of nuclear plants in Japan and presents scientific views on the resumption of their operations.

The rationality of the designated evacuation zone and handling of the accident at the Fukushima I Nuclear Power Plant in Japan

The accident at the Fukushima I Nuclear Power Plant in Japan on 11 March 2011 has led to widespread public exposure to high levels of radiation. At present, the government allows people to live in an area where the level of radiation is lower than 20 mSv/year. But, unless the level of radiation is reduced markedly to lower than 1 mSv/year, people should not be allowed to return to the area. Nevertheless, Nuclear Emergency Response Headquarters removed the designation of ‘zones in preparation for emergency evacuation’ on 30 September with this fundamental problem yet to be solved. The paper examines the legal context for this problem.

Porritoxins, metabolites of Alternaria porri, as anti-tumor-promoting active compounds

To search for possible cancer chemopreventive agents from natural sources, we performed primary screening of metabolites of Alternaria porri by examining their possible inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells. The ethyl acetate extract of A. porri showed the inhibitory effect on EBV-EA activation. Three porritoxins (1–3) were obtained as inhibitory active compounds for EBV-EA from ethyl acetate extract. 6-(3′,3′-Dimethylallyloxy)-4-methoxy-5-methylphthalide (2) showed the strongest activity among them. Inhibitory effect of porritoxin (1) and (2) was superior to that of β-carotene, a well-known anti-tumor promoter. Furthermore, the structure–activity correlation of porritoxins and their related compounds were discussed.

Efficient C–H activation of alkylbenzenes and methylcyclohexenes to benzyl esters by Pd(OAc)2/Sn(OAc)2 catalyst system

Selective activation of the side-chain C–H bond of alkylbenzenes and methylcyclohexenes is achieved by a Pd(OAc)2/Sn(OAc)2 catalyst system. Under an oxygen atmosphere, various benzyl esters were obtained from the substrates and carboxylic anhydrides. The esters were obtained in more than 100% yield based on the amount of benzoic anhydride, and consumption of oxygen was observed. This suggests that oxygen may be incorporated to produce two moles of the benzoxyl group from one mole of benzoic anhydride. It is interesting that either 1-, 3- or 4-methylcyclohexene reacted with benzoic anhydride to give benzyl benzoate. These carboxylations proceeded at the side-chain alkyl group with high selectivity and no ring-carboxylated product or coupling product was detected. From these results, a mechanism involving the formation of a η3-benzylpalladium complex was proposed.

Organic reactions using sodium hydrogentelluride: Part 4. The selective reduction of aromatic aldehydes or ketones with electron-withdrawing groups on the benzene ring by sodium hydrogentelluride

Aromatic aldehydes or ketones which have electron-withdrawing groups on the benzene ring were selectively reduced to the corresponding alcohols in good yields by sodium hydrogentelluride; common aldehydes such as benzaldehyde and tolualdehyde were inert.

Coping with Unexpected Incidents through Environmental Resilience to Promote Human Adaptation

When the Great East Japan Earthquake struck on March 11, 2011, a large number of people and organizations faced unexpected situations. Even under such circumstances, some people flexibly responded to the situation to minimize damage caused by the disaster beyond the codes of conduct, including manuals, laws, regulations, precedents, and procedures learned in training, that should otherwise have been complied with. Although some of them ended in failure, most yielded positive results for the following reasons: 1) the possibility of accidents was considered even before the earthquake to prevent them as much as possible; 2) when the unexpected occurred, people on the front line of the disaster voluntarily and autonomously made decisions and acted. It was suggested that, in the event of such a disaster as the earthquake in Tohoku, adaptation and resilience are required to respond to the situation, rather than relying on manuals. As a key point, it is important to enhance the abilities of individual persons and evaluate their efforts in each situation to improve the resilience of individuals and organizations, instead of assessing their approaches solely based on the results. Short Research Article British Journal of Education, Society & Behavioural Science, 4(1): 43-51, 2014 44